Comparison of the potential rate of population increase of brown and green color morphs of Sitobion avenae （Homoptera： Aphididae） on barley infected and uninfected with Barley yellow dwarf virus

Life tables of brown and green color morphs of the English grain aphid, Sitobion avenae （Fabricius） reared on barley under laboratory conditions at 20 ＋ 1℃,65% ± 5% relative humidity and a photoperiod of 16 ： 8 h （L ： D） were compared. The plants were either： （i） infected with the Barley yellow dwarf virus （BYDV）; （ii） not infectedwith virus but previously infested with aphids; or （iii） healthy barley plants, which were not previously infested with aphids. Generally, both color morphs of S. avenae performedsignificantly better when fed on BYDV-infected plants than on plants that were virus free but had either not been or had been previously infested with aphids. Furthermore,when fed on BYDV-infected plants, green S. avenae developed significantly faster and had a significantly shorter reproductive period than the brown color morph. There wereno significant differences in this respect between the two color morphs ofS. avenae when they were reared on virus-free plants that either had been or not been previously infestedwith aphids. These results indicate that barley infected with BYDV is a more favorable host plant than uninfected barley for both the color morphs ofS. avenae tested, particularly the green color morph.     

Elevation-related variation in the population characteristics of distylous Primula nivalis affects female fitness and inbreeding depression

The population characteristics of distylous species are highly sensitive to stochastic natural selection pressure.Therefore,populations growing under different environmental conditions may vary in floral morph ratios,potentially affecting female fitness and leading to inbreeding depression.However,the variation in offspring quality among populations as a result of inbreeding depression is poorly understood in distylous species.This study investigates variations in plant density,seed mass,seed viabilityfemale fitness,and post-dispersal inbreeding depression in both sexual morphs(long-styled and shortstyled plants)of the distylous Primula nivalis that were subjected to different pollination treatments along an elevational gradient from 1657 to 2704 m a.s.l.Population characteristics(morph plant density and ratio)and fruit set were significantly affected by sexual morph and elevation.Plant density and fruitset frequencies were lower for short-styled than for long-styled plants at 2704 m a.s.l.The seeds from the cross-pollinated flowers of both morphs were higher in quality than those of self-pollinated flowers.The female fitness of seeds from cross-pollinated flowers of both morphs was higher than that of seeds from open-pollinated and self-pollinated flowers.The female fitness of seeds from long-styled flowers was higher than that of seeds from short-styled flowers at all elevations.Inbreeding depression increased with elevation among plants with short-styled flowers but not among those with long-styled flowers.Variation in the elevation-dependent mating system might influence female fitness and affect inbreeding depression in both floral morphs.In conclusion,the low quality of seeds from short-styled flowers at high elevations might decrease short-styled flower frequency,affecting population characteristics.     

Assessment of candidate plant DNA barcodes using the Rutaceae family

DNA barcoding is a rapidly developing frontier technology that is gaining worldwide attention.Here,seven regions (psbA-trnH,matK,ycf5,rpoC1,rbcL,ITS2,and ITS) with potential for use as DNA barcodes were tested for their ability to identify 300 samples of 192 species from 72 genera of the family Rutaceae.To evaluate each barcode’s utility for species authentication,PCR amplification efficiency,genetic divergence,and barcoding gaps were assessed.We found that the ITS2 region exhibited the highest inter-specific divergence,and that this was significantly higher than the intra-specific variation in the "DNA barcoding gap" assessment and Wilcoxon two-sample tests.The ITS2 locus had the highest identification efficiency among all tested regions.In a previous study,we found that ITS2 was able to discriminate a wide range of plant taxa,and here we confirmed that ITS2 was also able to discriminate a number of closely related species.Therefore,we propose that ITS2 is a promising candidate barcode for plant species identification.     

The price of protection:a defensive endosymbiont impairs nymph growth in the bird cherry-oat aphid,Rhopalosiphum padi

Bacterial endosymbionts have enabled aphids to adapt to a range of stressors,but their effects in many aphid species remain to be established.The bird cherry-oat aphid,Rhopalosiphum padi(Linnaeus),is an important pest of cereals worldwide and has been reported to form symbiotic associations with Serratia symbiotica and Sitobion miscanthi L-type symbiont endobacteria,although the resulting aphid phenotype has not been described.This study presents the first report of R.padi infection with the facultative bacterial endosymbiont Hamiltonella defensa.Individuals of R.padi were sampled from populations in Eastern Scotland,UK,and shown to represent seven R.padi genotypes based on the size of polymorphic microsatellite markers;two of these genotypes harbored H.defensa.In parasitism assays,survival of H.defensa-infected nymphs following attack by the parasitoid wasp Aphidius colemani(Viereck)was 5 fold higher than for uninfected nymphs.Aphid genotype was a major determinant of aphid performance on two Hordeum species,a modern cultivar of barley H.vulgare and a wild relative H.spontaneum,although aphids infected with H.defensa showed 16%lower nymph mass gain on the partially resistant wild relative compared with uninfected individuals.These findings suggest that deploying resistance traits in barley will favor the fittest R.padi genotypes,but symbiontinfected individuals will be favored when parasitoids are abundant,although these aphids will not achieve optimal performance on a poor quality host plant.     

Aphid populations showing differential levels of virulence on Capsicum accessions

The green peach aphid,Myzus persicae,is one of the most threatening pests in pepper cultivation and growers would benefit from resistant varietices.Previously,we identified two Capsicum acessions as susceptible and three as resistant to M.persicae using an aphid population originating from the Netherlands(NL).Later on we identified an aphid population originating from a diferent gcographical region(Switserland,SW)that was virulent on all tested Capsicum acessions.The objeetive of the current work is to describe in detail diferent aspects of the interaction between two aphid populations and two sclected Capsicum acessions(one that was susceptible[PB2013046]and one that was resistant[PB2013071]to population NL),including biochemical processes involved.Electrical penetration graph(EPG)recordings showed similar feeding activities for both aphid populations on PB2013046.On acession PB2013071 the aphid population sw was able to devote significantly more time to phloem ingestion than population NL.We also studied plant defense response and found that plants of acession PB2013046 could not induce an accumulation of reactive oxygen species and callose formation after infestation with either aphid population.However,plants of PB2013071 induced a stronger defense response after infestation by population NL than after infestation by population SW.Based on these results,population SW of M.persicae seems to have overcome the resistance of PB2013071 that prevented feeding of aphids from NL population.The potential mechanism by which SW population overcomes the resistance is discussed.     

Application of DNA barcoding to the identification of Hymenoptera parasitoids from the soybean aphid （Aphis glycines） in China

Aphis glycines Matsumura is an important pest of soybean in Asia and North America. Hymenoptera parasitoids play a key role in the control of the soybean aphid. Thecorrect identification of parasitoids is a critical step that precedes the assessment of their potential biological control agents. Accurate identification of the majority of the speciesattacking the soybean aphid often requires elaborate specimen preparation and expert taxonomic knowledge. In this study, we facilitated the identification of soybean aphidparasitoids by applying a DNA barcoding approach following a preliminary morphological identification. We generated DNA sequence data from the mitochondrial COI gene andthe D2 region of 28S rDNA to assess the genetic variation within and between parasitoid species emerging from the soybean aphid in China. Fifteen Hymenoptera parasitoid speciesbelonging to 10 genera of five families were identified with little intra-specific variation （0.09% ± 0.06% for 28S and 0.36% ± 0. 18% for COI） and large inter-specific divergence（30.46% ± 3.42% for 28S and 20.4% ± 1.20% for COI）.     

Molecular Genetic Variation in a Clonal Plant Population of Leymus chinensis （Trin.） Tzvel.

Randomly amplified polymorphic DNA （RAPD） analysis was used to investigate the genetic variation among populations, between populations, and within populations, relationships between genetic distance and geographic distance, and the molecular variation and population size. The effects of geographic and genetic distances, as well as of genetic differentiation and population size, on genetic variations of Leymus chinensis （Trin.） Tzvel. are discussed. The present study showed that there was significant RAPD variation between the Baicheng region population and the Daqing region population, with a molecular variance of 6.35% （P 〈 0.04）, and for differentiation among area populations of the Daqing region, with a molecular variance of 8.78% （P 〈 0.002）. A 21.06% RAPD variation among all 16 populations among two regions was found （P 〈 0.001）, as well as 72.59% variation within populations （P 〈 0.001）. Molecular variation within populations was significantly different among 16 populations.     

拟澳洲赤眼蜂和短管赤眼蜂在米蛾卵上的种间竞争

By means of single and mixed inoculation, this paper studied the interspecific competition between T. confusum and T. pretiosum on the factitious eggs of Corcyra cephaloica under different parasitoid densities, host densities and inoculated spaces. The results showed that for both singly and mixed inoculated groups, the parasitism increased with parasitoid density but decreased with host density, whereas the percentage of female progeny dropped with parasitoid density but enhanced with host density. No significant effect was observed on adult emergence for all parasitoid and host density treatments. In mixed inoculated group, the proportion of T. pretiosum in the progeny decreased with parasitoid density but increased with host density, and was more than 50% in all treatments, indicating that T. pretiosum had a stronger competitive ability than T. confusum. In the spaces ranging from 4cm^3 to 102cm^3, the parasitism decreased gradually in both singly and mixed inoculated groups. The percentage of female progeny and adult emergence had no significant difference among different inoculated spaces. In mixed inoculated group, the proportion of T. pretiosum in the progeny was more than 50% in all treatments except space 102 cm3, but decreased with space, which suggested that T. confusum could improve their competitive ability through increasing their search areas and looking for more hosts.     

A web based tool to merge geometric morphometric data from multiple characters

Geometric morphometrics (GM) is an important method of shape analysis and increasingly used in a wide range of scientific disciplines.Presently,a single character comparison system of geometric morphometric data is used in almost all empirical studies,and this approach is sufficient for many scientific problems.However,the estimation of overall similarity among taxa or objects based on multiple characters is crucial in a variety of contexts (e.g.(semi-)automated identification,phenetic relationships,tracing of character evolution,phylogenetic reconstruction).Here we propose a new web-based tool for merging several geometric morphometrics data files from multiple characters into a single data file.Using this approach information from multiple characters can be compared in combination and an overall similarity estimate can be obtained in a convenient and geometrically rigorous manner.To illustrate our method,we provide an example analysis of 25 dung beetle species with seven Procrustes superimposed landmark data files representing the morphological variation of body features:the epipharynx,right mandible,pronotum,elytra,hindwing,and the metendosternite in dorsal and lateral view.All seven files were merged into a single one containing information on 649 landmark locations.The possible applications of such merged data files in different fields of science are discussed.     

Widespread infection and diverse infection patterns of Wolbachia in Chinese aphids

Wolbachia are intracellular symbionts that infect a wide range of arthropods and filarial nematodes. Aphids are engaged in diverse and complex relationships withtheir endosymbionts. Four supergroups （A, B, M and N） of Wolbachia were previously detected in aphids and supergroups M and N were only found in aphids. In this study, wedetected and described Wolbachia infections in natural populations of aphids in China. Three supergroups （A, B and M） were found in the examined aphid species. SupergroupM was preponderant, whereas supergroups A and B were only detected in certain species. Supergroup N was not found in this study. There were four infection patterns of Wolbachiain aphids, namely, infection with supergroup M alone, co-infection with supergroups A and M, co-infection with supergroups B and M, and co-infection with supergroups A, Band M. The pattern of infection only with supergroup M was universal and was tbund in all evaluated subfamilies. Only two subfamilies, Aphidinae and Lachninae, manifestedto present all four infection patterns. Three patterns were observed in Calaphidinae （M, A＆M, B＆M） and Eriosomatinae （M, B＆M, A＆B＆M）. Two patterns were observed inthe Anoeciinae （M, A＆M） and Greenideinae （M, B＆M）, and only one pattern （M） was observed in the remaining families and/or subfamilies of Aphidoidea. These results indi-cated that Wolbachia infections in Chinese aphids are widespread. Phylogenetic analyses suggest that Wolbachia supergroup M spread rapidly and recently among all host speciesof aphids in China. Reasons for this spread and its mechanisms are discussed along with the possible effects of Wolbachia on their aphid hosts.     

Microsporogenesis and meiotic behavior in nine species of the genus Pinus

The meiotic behavior of 10 taxa （nine species and one variety） of the genus Pinus was investigated using pollen mother cells （PMCs） to reveal the differentiation among karyotypes. Chromosome spreads were prepared by conventional squashing. The meiotic index and the average configuration were higher, whereas the frequency of aberrance （chromosomal bridges, fragments, or micronuclei） was lower, in all 10 taxa compared with other gynmosperms. The meiotic index, average configuration, and frequency of irregularity were found to be uniform among the species. It was shown that the genomes of the Pinus species investigated were highly stable, confirming results of previous mitotic analyses in this genus. However, slight differentiation of homologous chromosomes among genomes was revealed by analysis of meiotic configurations in Pinus nigra var. poiretiana. Quadrivalents were observed in 9.31% of PMCs in this species. This is the first time that quadrivalents have been observed in gymnosperms.     

Evaluating the Phylogenetic Position of Chinese Tree Shrew （Tupaia belangeri chinensis） Based on Complete Mitochondrial Genome： Implication for Using Tree Shrew as an Alternative Experimental Animal to Primates in Biomedical Research

Tree shrew(Tupaia belangeri) is currently placed in Order Scandentia and has a wide distribution in Southeast Asia and Southwest China.Due to its unique characteristics,such as small body size,high brain-to-body mass ratio,short reproductive cycle and life span,and low-cost of maintenance,tree shrew has been proposed to be an alternative experimental animal to primates in biomedical research.However,there are some debates regarding the exact phylogenetic affinity of tree shrew to primates.In this study,we determined the mtDNA entire genomes of three Chinese tree shrews(T.belangeri chinensis) and one Malayan flying lemur(Galeopterus variegatus).Combined with the published data for species in Euarchonta,we intended to discern the phylogenetic relationship among representative species of Dermoptera,Scandentia and Primates.The mtDNA genomes of Chinese tree shrews and Malayan flying lemur shared similar gene organization and structure with those of other mammals.Phylogenetic analysis based on 12 concatenated mitochondrial proteinencoding genes revealed a closer relationship between species of Scandentia and Glires,whereas species of Dermoptera were clustered with Primates.This pattern was consistent with previously reported phylogeny based on mtDNA data,but differed from the one reconstructed on the basis of nuclear genes.Our result suggested that the matrilineal affinity of tree shrew to primates may not be as close as we had thought.The ongoing project for sequencing the entire genome of Chinese tree shrew will provide more information to clarify this important issue.     

Global Warming： Can Existing Reserves Really Preserve Current Levels of Biological Diversity？

Peleoecologlcel evidence end peleoclimatlc records indicate that there wee e plant polewerd migration in latitude and an upward shift In elevation with increased temperatures after the last glaciation. Recent studies have shown that global warming over the past 100 years has been having a noticeable effect on living systems. Current global warming Is causing a poleward and upward shift In the range of many plants and animals. Climate change, In connection with other global changes, is threatening the survival of a wide range of plant and animal species. This raises the question： can existing reserves really preserve current levels of biological diversity In the long term given the present rapid pace of climate change？ The present paper deals with this question In the context of the responses of plants and animals to global climate change, based on a literature review. Consequently, we recommend expanding reserves towards the poles and/or towards higher altitudes, to permit species to shift their ranges to keep pace with global warming.     

Male-killer dynamics in the tropical butterfly,Acraea encedana （Lepidoptera： Nymphalidae）

Sex ratio distortion in the tropical butterfly Acraea encedana is caused by infection with a male-killing bacterium of the genus Wolbachia. Previous research on this species has reported extreme female bias, high bacterial prevalences, and full sex role reversal. In this paper, we provide an assessment for the dynamics of the male-killer, based on a survey for sex ratios and Wolbachia prevalences among wild populations of A. encedana in Uganda. The study reveals that Wolbachia infection showed considerable variation over both spatial and temporal scales.     

Aggregation and mating success of Capnodis tenebrionis （Coleoptera： Buprestidae）

An understanding of the relative importance of extrinsic and intrinsic factors in determining the potential distribution and mating success of individuals is critical for the successful monitoring and management of pest species. Using a combination of field observations and a caged field experiment, we explored the roles of environmental and individual variation on the formation of mating aggregations and mating success in the buprestid beetle Capnodis tenebrionis （Linnaeus, 1767）, a pest species of stone fruit trees. Our field observations revealed that the formation of aggregations is influenced by a range of environmental factors including temperature, photoperiod, and population density. However, aggregations were not at random and were more likely to occur on the section of the plant with highest incidence of solar radiation and thus higher temperatures. Data from our experiment with caged beetles in the field further indicate that the reproductive behavior of this species varies with temperature. The probability of a successful mating occurring was also positively related to both male and female size. Females of C. tenebrionis mate several times over a 4-h period, but generally not with the same male. Information obtained from these studies is useful to define the most appropriate time for pest control, especially adopting strategies that interfere with reproduction.     

BioCluster:Tool for Identification and Clustering of Enterobacteriaceae Based on Biochemical Data

Presumptive identification of different Enterobacteriaceae species is routinely achieved based on biochemical properties. Traditional practice includes manual comparison of each biochemical property of the unknown sample with known reference samples and inference of its identity based on the maximum similarity pattern with the known samples. This process is laborintensive, time-consuming, error-prone, and subjective. Therefore, automation of sorting and similarity in calculation would be advantageous. Here we present a MATLAB-based graphical user interface(GUI) tool named Bio Cluster. This tool was designed for automated clustering and identification of Enterobacteriaceae based on biochemical test results. In this tool, we used two types of algorithms, i.e., traditional hierarchical clustering(HC) and the Improved Hierarchical Clustering(IHC), a modified algorithm that was developed specifically for the clustering and identification of Enterobacteriaceae species. IHC takes into account the variability in result of 1–47 biochemical tests within this Enterobacteriaceae family. This tool also provides different options to optimize the clustering in a user-friendly way. Using computer-generated synthetic data and some real data, we have demonstrated that Bio Cluster has high accuracy in clustering and identifying enterobacterial species based on biochemical test data. This tool can be freely downloaded at http://microbialgen.du.ac.bd/biocluster/.     

The complete mitochondrial genome of the Keeled box turtle Pyxidea mouhotii and phylogenetic analysis of major turtle groups

The complete mitochondrial genome （16,837 bp） from the Keeled box turtle （Pyxidea mouhotii） was determined. The genome content, gene order, and base composition conformed to the consensus vertebrate type mtDNA. However, a remarkable feature was found in this molecule： a large number of （ATTATATC） n direct tandem repeats followed by （TA） n microsatellite at the 3＇ end of the control region （D-loop）, which might be useful as molecular markers for studying population genetics and helpful for species identification and conservation. Besides, to review phylogenetic relationships among major turtle lineages, maximum-likelihood （ML） and Bayesian （BI） analyses were conducted based on concatenated sequences of 13 protein-coding genes from 16 taxa. The resultant ML and BI analyses showed homological topologies, which only differed on the exact placement of Platysternon. Nevertheless, the results strongly supported that 1） Pyxidea mouhotii and Cuora aurocapitata formed a monophyletic clade, whereas Cyclemys atripons was not closer to the Pyxidea-Cuora than to Chinemys reevesii, suggesting that Cyclemys and the Cuora group （containing Pyxidea） may have originated from two ancestors; 2） the Geoemydidae with Testudinidae was a sister group rather than with the Emydidae.     

Is Tetranychus urticae suitable prey for development and reproduction of nafve Coleomegilla maculata？

The lady beetle Coleomegilla maculata De Geer is an omnivorous predator that could help suppress aphid and spider mite populations on plants in greenhouses, plantscapes or interiorscapes. We are assessing the nutritional requirements and feeding behavior of C. maculata on target prey （spider mites） and factitious （unnatural） food. Our ultimate goal is to develop an efficacious diet to mass produce C. maculata. In this study, we tested the hypothesis that Tetranychus urticae Koch （two-spotted spider mite） is not suitable prey for development and reproduction of naive C. maculata （i.e., with no prior exposure to T. urticae）. Our objectives were to （i） provide baseline data on the effects of consuming T. urticae on C. maculata life history, （ii） to compare the effects of consuming all stages of T. urticae versus eggs ofMusca domestica L. （common housefly）, and （iii） to determine if the consumption of plant products was beneficial. We used C. maculata from a colony reared only on Ephestia kuehniella Zeller （Mediterranean flour moth） eggs. In experiments, C. maculata larvae were reared from the first instar to adult stage with prey/food in replicated arenas; adult females were paired with a single male with prey/food. The results showed that naive C. maculata readily attacked and consumed T. urticae. Nevertheless, T. urticae was less suitable than M. domestica eggs for C. maculata development and reproduction. Applying a synthetic pollen-Chlorella alga powder （SPCA） in arenas containing T. urticae appeared to boost C. maculata female development and reproduction.     

Complete mitochondrial genome of Oxya chinensis （Orthoptera, Acridoidea）

The complete sequence of Oxya chinensis （0. chinensis） mitochondrial genome is reported here. It is 15,443 bp in length and contains 75.9% A＋T. The protein-coding genes have a similar A＋T content （75.2%）. The initiation codon of the cytochrome oxidase subunit I gene in the mitochondrial genome of O. chinensis appears to be ATC, instead of the tetranucleotides that have been reported in Locusta migratoria （L migratoria） mitochondrial genome. The sizes of the large and small ribosomal RNA genes are 1319 and 850 bp, respectively. The transfer RNA genes have been modeled and showed strong resemblance to the dipteran transfer RNAs, and all anticodons are identical to those of dipteran. The A＋T-rich region is 562 bp, shorter than that of other known Orthoptera insects. The six conserved domains were identified within the A＋T-rich region by comparing its sequence with those of other grasshoppers. The result of phylogenetic analysis based on the dataset containing 12 concatenated protein sequences confirms the close relation-ship of O. chinensis with L migratoria.